Anaemia
Red Flags — act before continuing history
| Red flag | Why dangerous | Action |
|---|---|---|
| Active GI bleeding — haematemesis or melaena | Upper GI haemorrhage causes rapid haemodynamic compromise. Melaena represents ≥50–100mL blood proximal to distal ileum — can coexist with apparently stable observations before sudden decompensation. Risk of Mallory-Weiss, peptic ulcer, oesophageal varices. | 999 immediately |
| Symptomatic Hb <70 g/L with tachycardia, breathlessness at rest, or haemodynamic instability | Cardiovascular compensation fails below Hb 60–70 g/L — risk of high-output cardiac failure, myocardial ischaemia, and end-organ hypoperfusion. Patients with pre-existing cardiac disease decompensate at higher Hb levels (<80 g/L). | Same-day hospital |
| Neurological features with B12 deficiency — unsteady gait, limb weakness, cognitive decline | Subacute combined degeneration of the spinal cord is irreversible if B12 replacement is delayed. Demyelination of dorsal and lateral columns progresses even when haematological features are absent or mild. | Urgent B12 + neurology |
| Unexplained IDA in men of any age or post-menopausal women — without obvious GI cause | Iron deficiency anaemia in men and post-menopausal women is caused by GI blood loss until proven otherwise. Colorectal cancer and upper GI malignancy are the most important causes — both potentially curable if detected early. NICE NG12 mandates 2WW referral. | 2WW referral — upper and/or lower GI |
| Unexplained weight loss (>5% in 3 months) with anaemia | Weight loss + anaemia = malignancy, lymphoma, or myelodysplasia until proven otherwise. The combination represents a constitutional B symptom pattern with haematological abnormality — urgent haematological and oncological investigation required. | 2WW referral + urgent bloods |
| Dysphagia with IDA — progressive difficulty swallowing | Dysphagia + IDA = 2WW upper GI referral (NICE NG12) to exclude oesophageal or gastric malignancy. Never attribute dysphagia to "reflux" in IDA without OGD. | 2WW upper GI |
| Pancytopenia — low Hb with low WCC and low platelets | Pancytopenia indicates bone marrow failure — aplastic anaemia, leukaemia, myelodysplastic syndrome, or marrow infiltration. Any two cell lines affected require urgent haematology review. Do not wait for repeat bloods — refer urgently on the initial FBC. | Urgent haematology |
Safeguarding Considerations — Consider in Every Consultation
🏠 Domestic Abuse / Intimate Partner Violence
- Chronic menorrhagia without prior medical help-seeking in a woman with IDA may reflect coercive control — the partner preventing medical attendance or disclosure
- Ask women about menstrual blood loss in a private setting, without family members present
- Recurrent presentations with anaemia but no clear cause: consider whether the patient is safe to disclose fully
- Routine IRIS/DASH enquiry in any woman with unexplained or recurrent IDA — "I ask all my patients: are you safe at home?"
👴 Older Adults / Carer-related Concern
- Unexplained IDA or B12 deficiency in a frail older adult with cognitive impairment may reflect inadequate nutrition or hydration by carers
- Consider whether the older patient has capacity to manage their own diet — poor dentition, swallowing difficulties, or social isolation can all cause nutritional anaemia
- Weight loss + anaemia in an older adult living with family carers: document a home visit or contact social services if neglect suspected
- Prescribed medications (metformin, PPIs) should be reviewed regularly in older adults with B12 deficiency to ensure they are still necessary
🧒 Children in the Household
- A parent presenting with anaemia due to nutritional deficiency may have children at home with the same inadequate diet — consider the whole family
- Iron deficiency in children under 2 years can cause irreversible cognitive impairment — ask about dietary history in any child attending with a parent who has IDA
- School-age child with chronic fatigue and pallor: if parents are reluctant to attend or history seems inconsistent, consider whether medical appointments are being blocked
- Referral to health visitor or school health team if a child's dietary iron intake appears inadequate
💊 Self-Harm / Eating Disorder / Medication Misuse
- IDA in a young woman with low BMI, lanugo, electrolyte disturbance, or parotid enlargement: consider anorexia or bulimia nervosa as the underlying cause
- Never attribute anaemia to "poor diet" in a young patient without exploring psychological relationship with food
- Non-adherence to prescribed iron due to GI side effects can be misread as treatment failure — explore barriers to taking medication gently before escalating dose
- Screen for depression and self-harm in any patient with unexplained recurrent anaemia and low BMI
🍽️ Food insecurity and dietary poverty
Red meat, oily fish, fortified cereals, and leafy green vegetables — the foods highest in bioavailable iron, B12, and folate — are also among the most expensive. Patients on low incomes or in food-insecure households are disproportionately affected by nutritional anaemia.
"I want to understand what your meals look like day-to-day — is it always possible for you to eat a varied diet?"If food insecurity identified: refer to social prescribing link worker, food bank, community dietitian. Iron supplementation is more effective than dietary advice in severe food poverty.
🍷 Alcohol misuse
Chronic alcohol use depletes folate through multiple mechanisms — poor dietary folate intake, impaired hepatic storage, increased renal excretion, and direct inhibition of folate-dependent enzymes. Also causes direct marrow suppression and, in cirrhosis, haemolysis. Folate supplementation alone will not resolve the anaemia while alcohol use continues.
"How much are you drinking at the moment? Some people find their drinking creeps up when they're stressed — has that been the case for you?"AUDIT-C score at every consultation. If hazardous/harmful drinking confirmed: Brief Motivational Intervention, written information, NHS Talking Therapies/alcohol service referral.
🧘 Dietary identity and eating attitudes
Veganism and vegetarianism are the fastest-growing dietary trends in the UK. B12 deficiency is near-universal in unsupplemented strict vegans over time. Disordered eating causes multi-nutritional deficiency anaemia. Framing dietary advice as "supplementation support" rather than criticism is essential for therapeutic alliance.
"It sounds like diet is something you've thought carefully about. I'd like to make sure your body is getting everything it needs — can we talk about supplements?"If disordered eating suspected: refer to NHS Talking Therapies, eating disorder service, or dietitian. Do not label dietary choices as "the problem."
💼 Work stress and shift work
High-demand work environments are associated with irregular meals, increased caffeine consumption (tannins inhibit iron absorption), and chronic physiological stress — which elevates cortisol and hepcidin, suppressing erythropoiesis. NHS workers, factory workers, and carers are disproportionately affected.
"With everything you've got going on at work, how's your eating — are you managing to have regular meals, or is it quite rushed?"Medication adherence is poor in shift workers — alternate-day iron dosing may improve adherence. Advise taking iron tablets at a consistent time.
🤰 Pregnancy and reproductive health
Pregnancy increases iron requirements dramatically — the fetus requires 300–350mg iron, and plasma volume expands by ~50%, diluting Hb. Multiparity without adequate iron repletion between pregnancies is a common cause of IDA. Pre-conception folate supplementation prevents neural tube defects.
"Are you thinking about having children in the future? There are some things we should think about now if so — including folate supplements before you try to conceive."Prescribe folic acid 400mcg daily (or 5mg if high-risk) from pre-conception until 12 weeks gestation. Refer to obstetric medicine if Hb <100 at booking.
🏠 Domestic situation and social isolation
Older adults living alone are at high risk of nutritional anaemia — they may be too tired or cognitively impaired to cook, surviving on tea, toast, and biscuits. Social isolation reduces motivation to prepare varied meals. Frail elderly patients with B12 deficiency may have been symptomatic for years before detection.
"Who looks after the cooking at home? Are you managing to eat well, or is it sometimes hard to motivate yourself to cook for one?"Consider referral to meals-on-wheels, social prescribing, Age UK, or occupational therapy. Annual B12 monitoring in all patients ≥65 years with known risk factors.
- Failing to ask about rectal bleeding or dark stools in a patient with IDA
- Asking "Are you tired?" when fatigue is the reason for attendance
- Not exploring what the patient thinks is causing the symptoms (ICE — Ideas)
- Not acknowledging the patient's cancer fear once it has been expressed
- Prescribing iron tablets at minute 3 before completing history (premature closure)
- Not asking about menstrual history in a woman of reproductive age or post-menopausal status
999 or Same-Day Hospital
Call 999 / A&E now- Active upper GI haemorrhage — haematemesis or melaena with haemodynamic instabilityTachycardia, hypotension, pallor, syncope — IV access and resuscitation needed
- Symptomatic Hb <70 g/L — rest breathlessness, chest pain, syncope, or presyncopeSame-day hospital medical assessment for blood transfusion consideration
- Severe anaemia precipitating cardiac ischaemia — angina or ECG changesAnaemia dramatically reduces oxygen delivery to ischaemic myocardium — treat as ACS + anaemia simultaneously
- Pancytopenia — severely low Hb with WCC <2 and/or platelets <50Possible aplastic anaemia or acute leukaemia — haematology same-day emergency admission
- Haemolytic crisis — rapid fall in Hb with jaundice, dark urine, feverIntravascular haemolysis — G6PD crisis, AIHA, TTP/HUS — emergency haematology
Same-Day GP / 2-Week Wait Referral
Days to 2 weeks- Unexplained IDA in any man or post-menopausal woman2WW lower and/or upper GI referral (NICE NG12) — do not treat without investigation
- IDA + rectal bleeding, change in bowel habit, or weight loss (≥60 years)2WW colorectal referral regardless of other features — FIT test before referral
- IDA + dysphagia or significant weight loss (any age)2WW upper GI referral — exclude oesophageal / gastric malignancy
- B12 deficiency with neurological features — tingling, numbness, balance problemsStart IM B12 immediately; urgent neurology referral if neurological signs confirmed on examination
- Anaemia + B symptoms (weight loss, drenching night sweats, fever)Urgent haematology referral — possible lymphoma or haematological malignancy
- Symptomatic anaemia Hb 70–90 g/L with cardiac disease or impaired functional capacitySame-day urgent clinical review — consider IV iron or inpatient transfusion pathway
Manage in Primary Care
GP practice- IDA in pre-menopausal woman with confirmed heavy periods and no red-flag featuresOral iron + menorrhagia management; recheck FBC at 4 weeks; no 2WW needed
- Dietary B12 deficiency in vegan/vegetarian without neurological featuresOral cyanocobalamin 50–150mcg daily; dietary advice; recheck B12 at 3 months
- Folate deficiency — dietary cause, AED-related, alcohol-related (with B12 excluded)Folic acid 5mg OD for 4 months; address underlying cause; recheck at 4 months
- Mild normocytic anaemia in known chronic disease (CKD 3, RA) — stable and asymptomaticOptimise underlying disease treatment; monitor with disease-specific review
- IDA confirmed post-investigation with benign cause identified (e.g. dietary, resolved menorrhagia)Oral iron for full treatment course (until Hb normal + 3 months more); dietary advice
- Starting oral iron in a post-menopausal woman or man without arranging GI investigation
- Failing to arrange 2WW referral when NICE NG12 criteria are clearly met
- Failing to start B12 immediately when neurological features are present
- Reassuring a patient with unexplained IDA that "it's probably nothing" before investigations are complete
- Omitting neurological examination when macrocytic anaemia or B12 deficiency is suspected
- Omitting abdominal examination in a patient with IDA and any GI symptoms
- Stating "I'd examine the patient" without specifying which examinations and their clinical rationale
- Failing to share examination findings with the patient in plain language after completion
- Requesting only FBC without ferritin, B12, and folate in a patient presenting with anaemia
- Failing to explain the investigation plan to the patient before taking blood
- Treating without investigating in a man or post-menopausal woman with IDA
- Starting folic acid without first checking and excluding B12 deficiency
"Think of your red blood cells like delivery vans — they carry oxygen from your lungs to every part of your body. When there aren't enough of them, or they aren't carrying enough oxygen, your body has to work harder to compensate — that's why your heart races, why you feel breathless climbing stairs, and why you feel so drained even after a good night's sleep. The blood test has confirmed you have anaemia — your red cells are lower than they should be, and the early results suggest it could be due to low iron. But I want to make sure we understand why your iron is low before we focus entirely on replacing it — because iron doesn't disappear on its own, and finding the cause is just as important as treating the numbers."
"I'm just tired — I've been working too hard and not sleeping well."
"I completely understand that — stress and poor sleep are exhausting, and they absolutely can make tiredness worse. But your blood test shows there's also something measurable going on — your iron is low — and it's really important we understand why, because tiredness alone doesn't cause iron deficiency. Something is either not absorbing iron properly, or causing you to lose it, and we need to find out what that is."
"I think I just need an iron tonic — my mum always said I ran low on iron."
"It's very possible that's part of what's going on, and we can certainly help with that. The important thing is that we also check why your iron is low — especially at your stage of life — because in some cases it can be a sign that something in the gut needs attention. Starting iron without checking would be like topping up a car tyre without looking for the puncture."
IDA — dietary or menstrual cause: Ferritin <30, microcytic picture, confirmed dietary cause or menorrhagia in pre-menopausal woman. Oral iron + address cause.
B12 deficiency — dietary (vegan/vegetarian): Low B12, no IFA, clear dietary history. Oral cyanocobalamin or dietary supplementation.
Folate deficiency — dietary or drug-related: Low folate, macrocytic picture, clear cause identified (alcohol, methotrexate, AED). Folic acid 5mg after B12 excluded.
Anaemia of chronic disease — stable, known cause: Normocytic, CRP elevated, established inflammatory condition (RA, IBD). Manage underlying condition.
Pernicious anaemia (autoimmune)
B12 deficiency + positive intrinsic factor antibodies + macrocytosis. Lifelong IM B12 required. GP initiates; haematology confirms.
Coeliac disease causing IDA
Positive TTG-IgA + IDA refractory to oral iron. Refer gastroenterology for duodenal biopsy before gluten-free diet.
Colorectal or upper GI malignancy
IDA in men/post-menopausal women = 2WW referral. Diagnosis confirmed by endoscopy — not by GP.
CKD-related anaemia (EPO deficiency)
Normocytic + eGFR <45 + low EPO. Nephrology for ESA consideration if Hb <100 on two consecutive readings.
Acute GI haemorrhage
Haematemesis or melaena with haemodynamic instability. 999 — hospital resuscitation and endoscopy.
Aplastic anaemia / acute leukaemia
Pancytopenia on FBC with severe anaemia. Emergency haematology admission — bone marrow biopsy required. Do not delay.
Haemolytic crisis
Rapid Hb drop + jaundice + dark urine + fever. Possible TTP, HUS, or AIHA haemolytic crisis. Emergency haematology admission.
- Using unexplained jargon: "microcytic hypochromic anaemia" without plain English equivalent
- Failing to address the cancer fear once it has been elicited or is clearly present
- Telling the patient they "definitely" have iron deficiency before investigations are complete
- Not explaining why investigation is needed before treatment starts
- Not mentioning the 2WW referral pathway when NICE NG12 criteria are met
- Delaying B12 loading doses until specialist appointment is confirmed
- Starting gluten-free diet advice before coeliac biopsy has been taken
- Telling the patient to wait until results are back before starting any treatment
Validate — name their expectation
The most common expectation in anaemia is "just give me iron tablets and let me get on with it." In post-menopausal women and men, complying without investigation is potentially dangerous. Validate the expectation before explaining why the plan may differ.
"I completely understand you'd like to feel better as quickly as possible — and I want that too. The iron is something we can start today."Explain — share your clinical reasoning
Share the reasoning behind investigating before (or alongside) treating. Use the "punctured tyre" analogy — topping up iron without finding the cause means it will run low again. Explain without alarming, but be honest about the purpose of the referral.
"The reason I want to investigate as well is that iron doesn't just disappear — your body is either not absorbing it properly, or losing it somewhere. If we just top it up without finding out why, it will keep falling."Negotiate — offer something today
Never leave the patient with nothing — always offer something concrete. Even when investigation must precede full treatment, iron tablets can often start in parallel. A clear follow-up plan and a named timeframe is essential for trust and adherence.
"So here is what I'd like to do today: I'll prescribe iron tablets, arrange the blood tests and stool test, and make the specialist referral — all happening together. We'll speak again as soon as the results are back."Haem iron (from meat and fish) is absorbed at 15–35% bioavailability — dramatically higher than non-haem iron (2–20%). Haem iron does not require gastric acid for conversion and is minimally affected by dietary inhibitors.
Beef, lamb, pork (85g portion = 2–3mg iron); sardines, mackerel (100g = 2mg). Liver is the richest source (10mg/100g) but avoid in pregnancy (excess vitamin A). Chicken and white fish are poorer sources.
Non-haem iron (spinach, lentils, beans, tofu, fortified cereals) requires reduction from Fe³⁺ → Fe²⁺ for absorption. Vitamin C (ascorbic acid) is the most potent enhancer — it donates electrons for this reduction and chelates iron to keep it soluble in the duodenum.
Glass of orange juice with iron tablet or iron-rich plant meal triples absorption. Tomatoes, peppers, strawberries, kiwi with iron-rich meals. Particularly important for vegans — non-haem iron is their only dietary iron source.
Tannins in tea and coffee form insoluble chelates with iron, reducing non-haem iron absorption by up to 60%. Phytates (in wholegrain bread, legumes) and polyphenols (in red wine) similarly inhibit absorption. Calcium (in dairy) competes with iron for the same intestinal transporter (DMT-1).
Avoid tea and coffee with meals and within 1 hour of iron tablets. Take iron on empty stomach with water or orange juice — if GI side effects, take with a small amount of food (not dairy). Do not combine calcium supplements with iron supplements.
B12 is found exclusively in animal products — meat, fish, eggs, dairy — and fortified foods (plant milks, nutritional yeast). Vegans who do not supplement have near-certain B12 depletion over years. Folate is heat-labile — destroyed by prolonged cooking.
For vegans: B12-fortified plant milk (3 cups/day = 2.4µg), nutritional yeast, or oral supplement (50–150mcg daily). For folate: leafy greens lightly steamed (not boiled), beans, lentils, fortified breakfast cereals. Fresh vegetables preferable to stored produce.
Alcohol depletes folate by impairing hepatic storage, reducing intestinal absorption, and increasing renal excretion. Direct bone marrow toxicity causes macrocytosis even without folate deficiency. Alcohol-related liver disease causes haemolysis via hypersplenism. MCV remains elevated for weeks after stopping.
Use AUDIT-C tool to screen and document. For hazardous/harmful drinking: Brief Motivational Intervention, written information, NHS Talking Therapies/alcohol service referral. In folate-deficient alcohol misusers: folate supplementation treats the haematological picture but does not replace the therapeutic work needed on alcohol reduction.
NSAIDs inhibit COX-1 → reduced prostaglandin synthesis → impaired gastric mucus production → mucosal damage → GI blood loss. Even low-dose aspirin (75mg) causes up to 2mL blood loss per day — sufficient to cause IDA in susceptible individuals.
Review indication for all NSAIDs — can paracetamol substitute? If NSAIDs or aspirin are essential: prescribe PPI gastroprotection (lansoprazole 30mg OD). Topical NSAIDs have lower GI risk but are not zero risk. Document NSAID review in the medical record.
Ferrous sulfate 200mg alternate days — preferred strategy
- Alternate-day dosing (e.g. Mon/Wed/Fri) is as effective as daily dosing with significantly fewer GI side effects — now the preferred strategy per BSH 2021
- Morning on empty stomach or with orange juice for maximum absorption
- If intolerance: try ferrous fumarate or ferrous gluconate (lower elemental iron content, better tolerated)
- Continue for 3 months after Hb has normalised to fully replenish stores (target ferritin ≥50 µg/L)
Hydroxocobalamin 1mg IM — pernicious anaemia or severe deficiency
- Loading: 1mg IM every other day for 6 doses (2 weeks), then maintenance
- Neurological involvement: 1mg IM 3×/week for 2 weeks, then 1mg every 2 months for first year
- Maintenance (pernicious anaemia): 1mg IM every 3 months lifelong — never stop
- Dietary deficiency: oral cyanocobalamin 50–150mcg daily is an appropriate alternative (NICE CKS)
Folic acid 5mg OD — ALWAYS exclude B12 deficiency first
- Treatment dose: 5mg OD for 4 months (dietary cause); continue if ongoing cause (haemolysis, malabsorption)
- Methotrexate co-prescription: 5mg once weekly (not on methotrexate day) — do not use treatment doses
- Pre-conception prophylaxis: 400mcg daily from ≥12 weeks before conception to 12 weeks gestation; 5mg if high-risk (previous NTD, BMI >30, diabetes, epilepsy)
- Haemolytic anaemia: 5mg OD ongoing to match increased folate consumption from rapid red cell turnover
Ferric carboxymaltose (Ferinject) 500–1000mg IV — preferred agent
- Indications: IBD (oral worsens disease), malabsorption (coeliac, bariatric surgery), oral intolerance despite alternate-day strategy, severe/symptomatic anaemia needing rapid correction, pre-operative anaemia, CKD, heart failure with iron deficiency (AFFIRM-AHF evidence)
- Dose calculated using Ganzoni formula or simplified body-weight chart; single infusion up to 1000mg achievable
- Hypophosphataemia: specific complication of ferric carboxymaltose — check phosphate 2–4 weeks post-infusion
- Anaphylaxis precautions: resuscitation equipment required; observe for 30 minutes post-infusion
- CKD 3b–5: IV iron preferred; target ferritin 200–500 µg/L; ESA (erythropoietin) only if Hb <100 after adequate iron repletion — nephrology-led decision
- Heart failure: IV iron (ferric carboxymaltose) proven to improve symptoms and exercise tolerance in HFrEF even without frank anaemia (AFFIRM-AHF trial); ferritin <100 or ferritin 100–300 with transferrin saturation <20%
- Pregnancy: IV iron (ferric carboxymaltose) after 14 weeks gestation if oral iron fails; target Hb ≥105 g/L at 28 weeks; 400mcg folate from pre-conception
- Cancer-related anaemia: Treat concurrent IDA with iron; ESA only in chemotherapy-related anaemia with haematology guidance
Select patient characteristics — consult drug reference cards in 7F for tailored recommendations
"Take the iron on alternate days — Monday, Wednesday, Friday — ideally on an empty stomach with a glass of orange juice. Your stools will turn black — this is normal and not a sign of bleeding. Avoid tea and coffee for an hour before or after taking the tablet."
SCA pearl: Pre-warning about black stools and alternate-day dosing prevents non-adherence — up to 30% of patients stop iron in the first week due to GI side effects. This counselling prevents the most common cause of treatment failure.
"This is an alternative form of iron that may be gentler on your stomach. Take it in the same way — with orange juice, away from tea and coffee. Your stools may still change colour slightly — this is completely normal."
SCA pearl: Knowing that ferric maltol (Feraccru) is a licensed oral iron option for IBD patients in remission demonstrates specific high-yield prescribing knowledge — a common examiner favourite in IBD-anaemia SCA cases.
"This is an iron infusion given through a drip — it takes about 15 minutes and delivers a much larger amount of iron than tablets can. You'll need to stay with us for 30 minutes afterwards to make sure you're well. Many people notice an improvement in energy within 2 to 3 weeks."
SCA pearl: Knowing when IV iron is indicated (IBD, malabsorption, intolerance, HFrEF, pre-operative) rather than defaulting to "increase the oral dose" is a high-yield differentiation marker in the Tasks domain — commonly tested in IBD or HFrEF SCA cases.
"This injection replaces the vitamin B12 your body can't absorb from food anymore. You'll need a course of 6 injections over 2 weeks to top up your stores, and then one injection every 3 months for the rest of your life. It sounds a lot, but most people manage it very well and really notice the difference."
SCA pearl: Explaining the lifelong injection commitment is the key SCA challenge in pernicious anaemia. Acknowledge the needle concern empathetically: "I know injections aren't everyone's favourite thing — most people tell me they barely notice it once they get into a routine."
"This tablet replaces a vitamin called folate that's important for making healthy red blood cells. You'll take it every day for 4 months. We've also checked your B12 vitamin — it's important that both are normal before starting."
SCA pearl: The absolute rule "always exclude B12 deficiency before starting folic acid" is one of the highest-yield exam facts in haematology. Prescribing folic acid without checking B12 in a macrocytic anaemia case is a significant Tasks domain deduction.
"We're giving you a blood transfusion to bring your blood count up to a safe level — this will help with the breathlessness and tiredness fairly quickly. We'll check your levels after each bag and decide together whether you need more. We'll also work on why your iron is low so we can treat the underlying cause."
SCA pearl: Knowing the transfusion threshold (Hb <70; <80 in cardiac patients) AND that transfusion does NOT substitute for corrective haematinic therapy in chronic anaemia are both high-yield Tasks domain facts.
Driving and occupational safety
Anaemia is not a DVLA notifiable condition, but severe anaemia (Hb <80 g/L) significantly impairs concentration, reaction time, and cognitive function — the same impairments that make driving dangerous. Patients should avoid driving if they feel faint, severely breathless, or cognitively impaired.
Occupations requiring physical exertion or precision work (healthcare, construction, operating machinery) may be temporarily affected. Occupational health referral is appropriate if severe anaemia is likely to persist for more than 2–4 weeks without rapid correction.
Post-treatment, most patients can resume all normal activities as Hb improves — set a clear expectation: 4–6 weeks for meaningful improvement with oral iron.
"While your blood count is this low, I'd ask you to take it easy with driving — particularly if you feel at all light-headed or faint. Once we've started treatment and your levels begin to rise, you should notice a real difference within a few weeks."Mental health, cognition, and memory
B12 deficiency is a well-recognised cause of cognitive impairment, depression, irritability, and in severe or prolonged cases, psychosis ("megaloblastic madness"). Patients with unexplained depression, anxiety, or cognitive decline should have B12 and folate checked as part of the initial work-up.
IDA in adults is associated with fatigue-driven depression, impaired concentration, and reduced executive function — these symptoms often resolve fully with treatment, and the patient should be told this to provide hope and motivation to adhere to treatment.
Screen with PHQ-9 if mood is significantly low — these are comorbidities, not caused solely by anaemia, but they interact and both need addressing.
"Some of the low mood and 'brain fog' you've described can be directly linked to your B12 levels — this is very treatable, and most people notice a significant improvement in their thinking and mood once their B12 is restored."Reproductive health and pregnancy
Anaemia significantly affects fertility and pregnancy outcomes. Severe IDA can disrupt ovulation. Untreated IDA in pregnancy is associated with preterm birth, low birth weight, and maternal haemorrhage at delivery.
Folic acid is essential for neural tube development — must begin at least 12 weeks before conception and continue to 12 weeks gestation. High-dose (5mg) if high-risk. B12 deficiency in pregnancy also increases NTD risk independently.
Hydroxocobalamin injections are safe in pregnancy. IV iron is safe after 14 weeks. Oral iron is first-line in pregnancy but nausea may be more challenging in the first trimester.
"Are you or your partner thinking about having children? There are some really important things we should sort out now — getting your iron levels up and making sure you're taking folic acid gives your baby the best possible start."Work performance and sick leave
Severe fatigue from anaemia is the most common reason for occupational impairment — reduced concentration, inability to complete physical tasks, and frequent sick leave. These consequences are often invisible to employers and may result in disciplinary action if the cause is not documented.
Providing a GP letter confirming a medical diagnosis with a predicted recovery timeline supports the patient in the workplace. A fit note may be appropriate for severe cases (Hb <80, symptomatic at rest) — plan for phased return once Hb begins to recover.
For shift workers or those with irregular eating patterns: alternate-day iron dosing at a consistent time is more likely to be adhered to than three-times-daily schedules.
"I want to make sure you're properly supported at work. I'm happy to write a letter explaining your diagnosis and what we're doing about it — that might help your employer understand why you've been struggling."Lifelong medication burden — B12 injections
Pernicious anaemia requires lifelong IM hydroxocobalamin injections every 3 months — this represents a permanent change in the patient's relationship with healthcare. For patients with needle phobia, this is a significant psychological burden that must be acknowledged and not minimised.
The 3-monthly injection schedule integrates into most patients' routines over time, but the initial commitment must be explained honestly and empathetically. If needle phobia is significant, refer for CBT or systematic desensitisation before forcing an injection approach.
During the first year, patients should understand that neurological recovery (if SACD was present) may be slow and incomplete — managing expectations prevents despair when improvement is slower than hoped.
"I know the idea of injections every three months forever sounds daunting. Most of my patients tell me that once they're in the routine, it becomes just another part of looking after themselves — and the improvement in how they feel makes it absolutely worth it."Dietary identity and cultural context
For vegan and vegetarian patients, framing dietary B12 or iron advice as "your diet is causing this" creates shame and may harm the therapeutic relationship. The GP's role is to supplement — not to change the diet — while providing factual information about the nutritional profile of plant-based diets.
Cultural dietary practices (halal restrictions, South Asian and East Asian dietary patterns, fasting during Ramadan) may affect iron and B12 intake. Explore cultural context before prescribing dietary changes — work within the patient's values.
Oral iron tablets are porcine-gelatine free (most NHS tablet formulations) — confirm this for patients who require halal or vegan preparations, and prescribe gelatine-free ferrous sulfate tablets or liquid formulations accordingly.
"Your diet sounds really thoughtful — I'm not suggesting you need to change it. What I'd like to do is make sure we supplement the nutrients that can be harder to get in sufficient quantities from plant-based foods alone."4 weeks — Initial treatment response (IDA)
Recheck FBC. Hb should have risen by ≥10 g/L and reticulocytosis should be visible on blood film. If no response: confirm diagnosis, check adherence, exclude ongoing blood loss, re-evaluate for malabsorption or alternative aetiology. IV iron if oral iron has failed despite confirmed IDA.
6–8 weeks — B12 treatment response
Recheck FBC and clinical neurological status after B12 loading is completed. MCV should begin to normalise and Hb should be improving. Check for concurrent iron deficiency — B12 treatment unmasks underlying IDA as marrow demand increases. Confirm whether cause is pernicious anaemia vs dietary.
3 months — Hb normalised; continue iron to replenish stores
Once Hb has normalised, oral iron should continue for a further 3 months to replenish iron stores (target ferritin ≥30–50 µg/L). Recheck ferritin. Address underlying cause — has menorrhagia been managed? Has coeliac biopsy been completed? Has alcohol been reduced?
6 months — Cause confirmed + ongoing management
Review 2WW investigation results. Confirm aetiology is documented and managed. Ensure coeliac, IBD, or other chronic disease management is optimised. Confirm pernicious anaemia patients are on the register for lifelong recall. Review prescriptions — is oral iron still needed?
Annual — Ongoing risk groups
Annual FBC + ferritin (± B12 + folate) in: pernicious anaemia patients (3-monthly B12 injection recall + annual bloods); patients on long-term metformin; patients with IBD, CKD, coeliac disease; post-bariatric surgery patients (iron, B12, folate, vitamin D annually); patients with menorrhagia until menopause; patients on long-term AEDs.
Memory rule — BIRD
Blood count at 4 weeks (IDA) or 8 weeks (B12 deficiency) — expect Hb rise ≥10 g/L. Iron stores (ferritin) at 3 months post-Hb normalisation — must reach ≥30 µg/L before stopping iron. Response failure = new investigation, not dose escalation. Duration: oral iron 3 months post-correction; B12 lifelong (pernicious anaemia); folate 4 months (treat cause simultaneously).
⚠ Three scenario-specific phrases — use these verbatim
Why safety-netting matters beyond clinical care
- Not summarising the plan back to the patient before ending the consultation
- Not checking whether the patient has any remaining questions (closing question)
- Failing to address cancer anxiety that was raised earlier in the consultation
- Giving a management plan without explaining why each element is needed
- Not naming when the patient will next hear from the practice
- Safety-netting in vague terms: "come back if you're worse" rather than naming specific symptoms and a specific action
- Correct identification of anaemia type by MCV and clinical context
- Red flags elicited and correctly actioned (2WW where indicated; B12 with neuro = start B12 immediately)
- Appropriate investigations planned (FBC + ferritin + B12 + folate minimum; FIT test)
- Correct first-line treatment selected (oral iron for IDA; IM B12 for pernicious anaemia; folic acid only after B12 excluded)
- Underlying cause addressed in the management plan (not just the Hb)
- Named follow-up with specific timeframe and results communication plan
- Open question used to begin consultation; patient given time to lead
- ICE fully explored: idea about cause named, concern (cancer fear) addressed, expectation acknowledged and negotiated
- Diagnosis explained in plain language — anaemia analogy, cause explanation, reason for investigation
- Shared decision-making explicit — patient agrees to management plan
- Empathy demonstrated specifically regarding cancer fear, needle phobia (B12), or lifestyle concern
- Closing question asked: "Is there anything else?" — mandatory for full RO marks
Who you are
Mrs Sarah Thornton, 52 years old. Primary school teacher — you love your job but it's busy and demanding. Post-menopausal for 18 months (last period was 18 months ago). You take ibuprofen daily for chronic lower back pain and drink about 2 glasses of wine most evenings. You stopped eating red meat 5 years ago for ethical reasons and eat mostly pasta, salads, and bread. You haven't had a blood test in several years.
Hidden agenda
Your mother died of bowel cancer at the age of 62. You've been having some vague right-sided abdominal discomfort for about 6 weeks but haven't told anyone because you're frightened it might be cancer. You're convinced that if you say it out loud, it will become real. If the doctor asks about bowel symptoms, you'll initially say "no" but will admit to the abdominal pain and occasional loose stools if asked sensitively and directly. You haven't noticed any blood in your stools — you've checked. Your real fear is cancer, not the tiredness.
Symptoms if asked directly
- Tiredness for about 3 months — "I feel exhausted even after a full night's sleep"
- Breathlessness climbing stairs at school — new over the past month
- Cold all the time — "I used to be warm, now I'm always freezing"
- Hair falling out more than usual in the shower
- Nails feel thin and brittle
- No rectal bleeding if asked directly (honestly)
- Right-sided abdominal discomfort (admits if asked twice, sensitively)
- Stools have been slightly looser for about 6 weeks (admits if directly asked)
- No weight loss
- No night sweats
Lifestyle + bonus details
- Eats mostly plant-based — pasta, vegetables, bread, cheese. No red meat for 5 years. Does eat fish about once a week.
- Drinks 2 glasses of wine most evenings (approx 14 units/week — at the upper limit of safe drinking)
- Takes ibuprofen 400mg up to three times daily for back pain (has not seen anyone about this recently)
- Does not take vitamin supplements
- Bonus detail if asked about tea/coffee: "I drink about 4–5 cups of tea a day, usually with my meals"
- Moderate exercise — walks to work, but stopped going to the gym when she got tired
Resolution: The patient accepts the plan if the candidate: (1) explicitly acknowledges her cancer fear by name without dismissing it ("I understand why that's in your mind, especially given your mother's history — and that's exactly why we need to investigate carefully"); (2) explains that investigation will happen quickly under the 2-week wait pathway; (3) offers something tangible today (iron tablets + blood tests), with a clear results timeline and personal contact. The patient will NOT accept a plan that only involves waiting for blood results before starting treatment, or one that dismisses the cancer concern without addressing it.
- Hb <70 g/L with cardiovascular compromise
- Active haemorrhage — haematemesis / malaena
- Neurological B12 deficiency — SACD suspected
- Haemolytic anaemia (jaundice + falling Hb)
- Aplastic crisis (sickle cell / thalassaemia + fever)
- IDA — man or post-menopausal woman (NICE NG12 2WW)
- Unexplained iron deficiency — any age without clear cause
- Rectal bleeding + IDA → 2WW colorectal
- Dysphagia + IDA → 2WW upper GI
- Weight loss + anaemia → 2WW appropriate pathway
- Pre-menopausal woman with heavy periods + IDA
- Dietary B12 / folate deficiency (vegan, poor diet)
- Anaemia of chronic disease — stable comorbidity
- Pregnancy-related anaemia — routine ANC pathway
IDA (ferritin <30) · Thalassaemia (normal/high RBC) · ACD with iron deficiency · Sideroblastic anaemia
ACD · CKD · Haemolysis · Acute blood loss · Mixed deficiency (B12+iron together)
B12 deficiency · Folate deficiency · Alcohol · Hypothyroidism · MDS · Methotrexate / hydroxyurea
| Drug / situation | Test | Timing | Action threshold |
|---|---|---|---|
| Oral iron (IDA) | FBC | 4 weeks | Hb rise <10 g/L → reassess cause, adherence, absorption |
| Oral iron (IDA) | FBC + ferritin | 3 months post-normalisation | Ferritin <50 µg/L → continue iron; Hb normal + ferritin replete → stop |
| IV iron (Ferinject) | Serum phosphate | 2–4 weeks post-infusion | Hypophosphataemia — specific complication of ferric carboxymaltose |
| Hydroxocobalamin IM | FBC | 8 weeks | MCV normalisation and Hb rise confirms response; B12 level not useful for monitoring IM therapy |
| Folic acid | FBC + B12 recheck | 4–8 weeks | If macrocytosis persists, review B12 status and alcohol intake |
| Metformin (>5 years) | Serum B12 | Annual | B12 <150 ng/L or symptoms → start IM hydroxocobalamin |